Bump github.com/stretchr/testify from 1.4.0 to 1.5.1

Bumps [github.com/stretchr/testify](https://github.com/stretchr/testify) from 1.4.0 to 1.5.1.
- [Release notes](https://github.com/stretchr/testify/releases)
- [Commits](https://github.com/stretchr/testify/compare/v1.4.0...v1.5.1)
Signed-off-by: dependabot-preview[bot] <support@dependabot.com>

go.mod

@@ -2,6 +2,6 @@ module github.com/libp2p/go-reuseport
 
 require (
 	github.com/pkg/errors v0.9.1
-	github.com/stretchr/testify v1.4.0
+	github.com/stretchr/testify v1.5.1
 	golang.org/x/sys v0.0.0-20190228124157-a34e9553db1e
 )

go.sum

@@ -14,6 +14,8 @@ github.com/stretchr/testify v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
+github.com/stretchr/testify v1.5.1 h1:nOGnQDM7FYENwehXlg/kFVnos3rEvtKTjRvOWSzb6H4=
+github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
 golang.org/x/sys v0.0.0-20190228124157-a34e9553db1e h1:ZytStCyV048ZqDsWHiYDdoI2Vd4msMcrDECFxS+tL9c=
 golang.org/x/sys v0.0.0-20190228124157-a34e9553db1e/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=